Problem in probability sensitivity analysis (PSA) for a partitioned survival (PartSA) model
I recently encoutered a problem when doing the PSA for my PartSA model.
I used literature reported numbers to calculate the parameters of exponential distribution for the progression free survival (PFS) and the overall survival (OS) of a cancer treatment, and then assign normal distributions to those parameters.
But as PFS and OS curves only seprate mildly and the confidence interval for survival time is large, when doing Monte Carlo simulation, there are considerable possibilities of drawing numbers that makes the survival curve cross.
Do you know if there is a way to make sure that the number drawed from OS would always be greater than the number drawed from PFS so that the survival curve wound not cross please? Thank you so much!